[ Upstream commit 119c4f5085c45b60cb23c5595e45d06135b89518 ]
The mutex for the regulator_dev must be controlled by the caller of the regulator_notifier_call_chain(), as described in the comment for that function.
Failure to mutex lock and unlock surrounding the notifier call results in a kernel WARN_ON_ONCE() which will dump a backtrace for the regulator_notifier_call_chain() when that function call is first made. The mutex can be controlled using the regulator_lock/unlock() API.
Fixes: e4ee831f949a ("regulator: Add WM831x DC-DC buck convertor support") Suggested-by: Adam Thomson Adam.Thomson.Opensource@diasemi.com Signed-off-by: Steve Twiss stwiss.opensource@diasemi.com Acked-by: Charles Keepax ckeepax@opensource.cirrus.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/regulator/wm831x-dcdc.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/regulator/wm831x-dcdc.c b/drivers/regulator/wm831x-dcdc.c index 12b422373580c..d1873f94bca74 100644 --- a/drivers/regulator/wm831x-dcdc.c +++ b/drivers/regulator/wm831x-dcdc.c @@ -183,9 +183,11 @@ static irqreturn_t wm831x_dcdc_uv_irq(int irq, void *data) { struct wm831x_dcdc *dcdc = data;
+ regulator_lock(dcdc->regulator); regulator_notifier_call_chain(dcdc->regulator, REGULATOR_EVENT_UNDER_VOLTAGE, NULL); + regulator_unlock(dcdc->regulator);
return IRQ_HANDLED; } @@ -194,9 +196,11 @@ static irqreturn_t wm831x_dcdc_oc_irq(int irq, void *data) { struct wm831x_dcdc *dcdc = data;
+ regulator_lock(dcdc->regulator); regulator_notifier_call_chain(dcdc->regulator, REGULATOR_EVENT_OVER_CURRENT, NULL); + regulator_unlock(dcdc->regulator);
return IRQ_HANDLED; }